The subject invention relates to a seat adjustment assembly for adjusting the height of a seat cushion.
Automotive seats include a number of adjustment devices for adjusting a relative position of the seat to a passengers particular comfort needs. The adjustment devices typically include manual and/or power mechanisms which recline a seat back, move the seat cushion for and aft, raise or lower the seat cushion, tilt the seat cushion, adjust a lumbar support and/or adjust the relative position of a headrest.
There are numerous devices which raise, lower and tilt the seat cushion which have been contemplated by the prior art. Examples of such devices are disclosed in U.S. Pat. Nos. 4,653,807, 5,123,622 and 5,765,840 and in British Patent No. 2 303 059. The prior art devices incorporate complicated linking mechanisms, cables, servos, ratchet and pawls and other components. In addition, many of the prior art devices incorporate added parts to ensure a desired range of lifting or tilting motion and to ensure the raised seat cushion can support the weight of the passenger.
There is a need for a seat cushion adjustment mechanism which is of a relatively simple design and utilizes a minimum number of parts while still ensuring a proper range of motion and being able to support the weight of a passenger.
An automotive seat adjustment assembly adjusts a relative position of a seat cushion. The adjustment assembly comprises at least one front mounting bracket adapted for supporting a forward end of the seat cushion and at least one rear mounting bracket adapted for supporting a rearward end of the seat cushion. At least one front seat support is movably mounted to the front mounting bracket and adapted for mounting to the forward end of the seat cushion. The front seat support is movable between a first position with the seat cushion in a lowered orientation and a second position with the seat cushion in a raised orientation. At least one rear seat support is movably mounted to the rear mounting bracket and adapted for mounting to the rearward end of the seat cushion. The rear seat support is movable between a first position with the seat cushion in a lowered orientation and a second position with the seat cushion in a raised orientation. At least one drive plate interconnects one of the front and rear mounting brackets with a corresponding front and rear seat support. A drive arm, having first and second ends, has the first end mounted to the drive plate and is movable between actuated and non-actuated positions for moving the corresponding front and rear seat support between the first and second positions to move the seat cushion between the lowered and raised orientations. A cam is connected to the second end of the drive arm for selectively moving the drive arm between the actuated and non-actuated positions to move the front and rear seat supports and the seat cushion.
Accordingly, the subject invention is of a relatively simple design essentially comprising a set of links for the forward and rearward ends of the seat cushion in order to move either or both ends of the seat cushion. The adjustment assembly of the subject invention does not incorporate any additional parts in order to limit the range of movement or for supporting the entire weight of a passenger.